package com.haitai.haitaitv.component.util;

import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.math.BigDecimal;
import java.math.MathContext;
import java.util.ArrayList;

import javax.imageio.ImageIO;

/***
 * 对图片进行操作
 * 
 * @author chenzheng_java
 * @since 2011/7/29
 * 
 */
public class ImageHelper {

    private static ImageHelper imageHelper = null;

    public static ImageHelper getImageHelper() {
        if (imageHelper == null) {
            imageHelper = new ImageHelper();
        }
        return imageHelper;
    }
    
    public static void main(String[] args) {
        ImageHelper.scaleImage("E:\\test.jpg", "E:\\test2.jpg", 1.2, "jpg");
        
    }

    /***
     * 按指定的比例缩放图片
     * 
     * @param sourceImagePath
     *            源地址
     * @param destinationPath
     *            改变大小后图片的地址
     * @param scale
     *            缩放比例，如1.2
     */
    public static void scaleImage(String sourceImagePath, String destinationPath, double scale, String format) {

        File file = new File(sourceImagePath);
        BufferedImage bufferedImage;
        try {
            bufferedImage = ImageIO.read(file);
            int width = bufferedImage.getWidth();
            int height = bufferedImage.getHeight();

            width = parseDoubleToInt(width * scale);
            height = parseDoubleToInt(height * scale);

            Image image = bufferedImage.getScaledInstance(width, height,
                    Image.SCALE_SMOOTH);
            BufferedImage outputImage = new BufferedImage(width, height,
                    BufferedImage.TYPE_INT_RGB);
            Graphics graphics = outputImage.getGraphics();
            graphics.drawImage(image, 0, 0, null);
            graphics.dispose();

            ImageIO.write(outputImage, format, new File(destinationPath));
        } catch (IOException e) {
            System.out.println("scaleImage方法压缩图片时出错了");
            e.printStackTrace();
        }

    }

    /***
     * 将图片缩放到指定的高度或者宽度
     * 
     * @param sourceImagePath
     *            图片源地址
     * @param destinationPath
     *            压缩完图片的地址
     * @param width
     *            缩放后的宽度
     * @param height
     *            缩放后的高度
     * @param auto
     *            是否自动保持图片的原高宽比例
     * @param format
     *            图图片格式 例如 jpg
     */
    public static void scaleImageWithParams(String sourceImagePath,
            String destinationPath, int width, int height, boolean auto,
            String format) {

        try {
            File file = new File(sourceImagePath);
            BufferedImage bufferedImage = null;
            bufferedImage = ImageIO.read(file);
            if (auto) {
                ArrayList<Integer> paramsArrayList = getAutoWidthAndHeight(
                        bufferedImage, width, height);
                width = paramsArrayList.get(0);
                height = paramsArrayList.get(1);
                System.out.println("自动调整比例，width=" + width + " height="
                        + height);
            }

            Image image = bufferedImage.getScaledInstance(width, height,
                    Image.SCALE_DEFAULT);
            BufferedImage outputImage = new BufferedImage(width, height,
                    BufferedImage.TYPE_INT_RGB);
            Graphics graphics = outputImage.getGraphics();
            graphics.drawImage(image, 0, 0, null);
            graphics.dispose();
            ImageIO.write(outputImage, format, new File(destinationPath));
        } catch (Exception e) {
            System.out.println("scaleImageWithParams方法压缩图片时出错了");
            e.printStackTrace();
        }

    }

    /**
     * 将double类型的数据转换为int，四舍五入原则
     * 
     * @param sourceDouble
     * @return
     */
    private static int parseDoubleToInt(double sourceDouble) {
        int result = 0;
        result = (int) sourceDouble;
        return result;
    }

    /***
     * 
     * @param bufferedImage
     *            要缩放的图片对象
     * @param width_scale
     *            要缩放到的宽度
     * @param height_scale
     *            要缩放到的高度
     * @return 一个集合，第一个元素为宽度，第二个元素为高度
     */
    private static ArrayList<Integer> getAutoWidthAndHeight(
            BufferedImage bufferedImage, int width_scale, int height_scale) {
        ArrayList<Integer> arrayList = new ArrayList<Integer>();
        int width = bufferedImage.getWidth();
        int height = bufferedImage.getHeight();
        double scale_w = getDot2Decimal(width_scale, width);

        System.out.println("getAutoWidthAndHeight width=" + width + "scale_w="
                + scale_w);
        double scale_h = getDot2Decimal(height_scale, height);
        if (scale_w < scale_h) {
            arrayList.add(parseDoubleToInt(scale_w * width));
            arrayList.add(parseDoubleToInt(scale_w * height));
        } else {
            arrayList.add(parseDoubleToInt(scale_h * width));
            arrayList.add(parseDoubleToInt(scale_h * height));
        }
        return arrayList;

    }

    /***
     * 返回两个数a/b的小数点后三位的表示
     * 
     * @param a
     * @param b
     * @return
     */
    public static double getDot2Decimal(int a, int b) {

        BigDecimal bigDecimal_1 = new BigDecimal(a);
        BigDecimal bigDecimal_2 = new BigDecimal(b);
        BigDecimal bigDecimal_result = bigDecimal_1.divide(bigDecimal_2,
                new MathContext(4));
        Double double1 = new Double(bigDecimal_result.toString());
        System.out.println("相除后的double为：" + double1);
        return double1;
    }

}
